The moan comes unbidden as I dip my nose into the glass bell that I've just lifted off Frédéric Malle's new Tubereuse candle. This must be what it feels like to be a moth hovering over moon-pale blossoms: not a perfume, but the very scent of a sprig, cool green over creamy-smooth floral flesh. Once my cortex reboots, I dart from the bell to a blotter sprayed with Carnal Flower, a resistance-is-futile tribute to the tuberose I've worn so often that some of it must be tattooed into my DNA. The scent's creator, perfumer Dominique Ropion—who also gave us Thierry Mugler Alien and Viktor & Rolf Flowerbomb—is considered one of the foremost specialists of white flowers. When I interviewed him two years ago for my book The Perfume Lover, he said his first version of Carnal Flower was a vividly realistic rendition, based on scientific analysis, "but it was an odor, not a perfume."

To turn one into the other, he had to tweak his formula. According to the Frédéric Malle website, the candle is actually Carnal Flower "without the connecting piece that makes it mingle with the skin." So, what's the missing link?

Teasing the Carnal Out of the Flower

When the poet Charles Baudelaire wrote that his lover's tresses smelled "of oil of coconut, of musk, and tar," he honed in on one of those "connecting pieces." With their fatty-buttery hay, peach, and coconut facets, lactones (from the Latin for "milk") are the molecules that add an irresistible creaminess to the scent of white flowers such as tuberose, jasmine, and gardenia, but also to peaches, plums, mangos, and figs—all notes which are frequently married to flowers in fine fragrance, from Guerlain's Mitsouko in 1919 to the recent Bottega Veneta. The lactone family also includes the natural musks contained in angelica (the green bits in Christmas cakes) and ambrette (extracted from hibiscus seeds). It just so happens our bodies host microscopic lactone factories: They're churned out by certain types of yeast, naturally present on skin and scalp, after they've feasted on sebum. Ropion tells me that it was precisely by "playing on the proportions of lactones and even on certain proteins found in milk but also in tuberose" that he turned his flower carnal.

Indole is another such link. The molecule is produced when certain types of protein decompose. On its own, it smells of mothballs or drops of rain on hot tar. Highly diluted, it veers towards the floral. Flowers like orange blossom, gardenia, jasmine, tuberose, lily, lily-of-the-valley, lilac, and wisteria puff it out. So do we, after eating protein-based food or when we're pushing up the daisies—it is this touch of decay that gives the femmes fatales of the garden their intoxicating headiness.

The Paradox of Musk

Musk is another of the "connecting pieces" Ropion added to turn his photo-realistic portrait of the tuberose into Carnal Flower. Perfumers love the stuff, and it loves them right back: a magic-bullet ingredient that can cover up gaps in wonky formulas, boost other notes, expand their volume and bind them to skin for hours (since synthetic musks are zaftig molecules that take a lot of body heat to fly off in the air—as opposed to tiny, excitable citrus essences). And since detergents and fabric softeners have been overloaded with them for decades, musks are also culturally bound with the smell of the skin our clean laundry rubs off onto.

Musk-themed perfumes can span the entire spectrum between feral and fresh-out-of-the-dryer. Kiehl's Original Musk¸ for instance, contains almost nothing but Galaxolide, a typical "laundry" musk, while Parfum d'Empire's limited-edition Musc Tonkin, inspired by the suave smell of animal musk, amps up its ripeness to bodice-ripping intensity. Narciso Rodriguez For Her inhabits the Goldilocks zone. I suspect it owes its iconic status to the exquisite balance it strikes between the angel and the animal, much like the designer manages to slide chick-a-boom curves under minimalist lines. The Extrait de Parfum version—its gel-like texture slicking on like a lover's sweat—may well be the ultimate skin-loving fragrance.

Mysterious Skin

Clearly, the co-authors of Narciso Rodriguez For Her are masters of the secret alchemy that makes a scent mingle with skin, and it is to them I turn for further insights. After signing such best-sellers as Jean Paul Gaultier Le Male and Armani Mania, Francis Kurkdjian went on to found his own eponymous house. He is the first perfumer in the world to have put his name to a detergent, Aqua Universalis (also available as a cologne).

But he's also expressed his bent for the dark side with his contribution to an anthology of perfumers' writings (Le Parfum: Histoire, Anthologie, Dictionnaire, published in 2011), in which he recounts a story of olfactory slumming that ends with a lap dancer "tattooing on my skin the odoriferous meanders of her triumphant, dominating body." With his Absolue Pour le Soir, he walks his smelly talk. The first time I smelled the fragrance, I burst out laughing at the sheer gutsiness of it. Underneath the boudoir fluff of benzoin, with its milk and vanilla facets, a smoky-milky blend of rose, honey and sandalwood laced with cumin conjures the scent of a woman's body, wafting up from a leather sheath. And indeed, when I ask him about it, Kurkdjian confirms: "Perfume is an artifice. You have to give it a form of humanity so that it will become one with the person wearing it. Certain notes or even certain accords help you find that state." He goes on to quote the usual suspects as examples: "Softly animalic notes such as civet, warm leather notes like castoreum, and let's not forget cumin and its smell of sweat if it is overdosed." But also, more surprisingly, he also employs "iris butter absolute, which to me conjures a fresh, slightly milky skin smell" (he uses it in his shimmering new Amyris Femme), and a synthetic material called methyl ionone that gives off powdery violet, iris and wood facets, because "it conjures the sexual smell of a woman."

As I start wondering whether my obsession with Serge Lutens's classic Féminité du Bois, which features the latter along with the leathery/honeyed atlas cedar, might not spring from some waywardly erotic olfactory narcissism, Kurkdjian adds: "But it's more a matter of making these materials resonate in an accord than of the raw material in itself. It's all a question of proportion and balance."

"Some smells are more carnal than others and melt more easily into the skin," agrees Christine Nagel, Kurkdjian's creative partner for the Narciso Rodriguez (she also authored Dolce & Gabbana The One and the original version of Miss Dior Chérie). But others speak to us because we associate them with innocence. "In France, it's vanilla and orange blossom. In the USA, it's the rose and musk accord of Johnson's Baby Powder." Just as I suspected, the secret of Narciso Rodriguez For Her's addictive nature, she says, is the way its fluffy, "regressive" haze—orange blossom, vanilla, musk and, in the Eau de Parfum, rose—wraps around subtly animalic notes such as osmanthus, a Chinese flower that smells like the impossible hybrid of fruit, blossom, and beast, its delicate apricot and suede facets conjuring downy skin.

In fact, Nagel explains, aside from the way certain notes can suggest the smells of the human body, the resonance between scent and flesh can also occur through the sensuous images and textures some elements suggest: the yielding softness of jasmine petals; the honeyed pulp of a sun-warmed fig; the velvet of peach skin over firm, juicy flesh. In other words, in the way perfumes play on recollections hovering at the edge of consciousness.

"Every time I run into a person wearing one of my fragrances, I tell myself they're wearing a little bit of me," Nagel confesses. Perhaps the secret of the alchemy between skin and scent is not to be found in the perfumers' chemistry set but in their minds? Or rather, in the encounter of their imagination with ours, as we weave their olfactory tales into our own. The difference between a fragrance that feels like it's just walking next to us and one that feels like an extension of our aura may well spring from this unspoken intimacy.

About the author: Denyse Beaulieu, a Canadian writer based in Paris, is the author of the fragrance blog Grain de Musc. Her book> The Perfume Lover: a Personal History of Scent came out in March 2012 in the U.K. It will be launched in the United States on March 19, 2013, by St. Martin's Press.